1. Field of the Invention
The invention relates generally to database management structures and techniques and more specifically relates to improved structures and methods for importation of data from a source database to a target database using an auxiliary database for retaining information not directly translatable in a streaming translation process from the source to the target database.
2. Discussion of Related Art
In general, databases store data with associated structure and information that relates the stored data to other stored data in the database and typically stores the data using indexing techniques and structures to permit rapid access to the data based on selected key or index values and attributes.
In a modern database, connections or joins between database elements may be as important as the field values of the elements. This is especially true in spatial databases, such as those used in conjunction with a Geographic Information System (GIS), or a Computer Aided Design or Drafting (CAD) Tool. For example, it is useful to record whether a particular item of equipment resides at a given street address. In a densely populated neighborhood, such information cannot be accurately indicated through physical proximity, so a logical join is required.
Another fact of modern commerce is that enterprises frequently translate data from one GIS or CAD Tool database to another. Currently, tools for translation are highly developed for smoothly transferring individual entity data, but require difficult programming steps in order to capture and translate join data. One of the main difficulties occurs during streaming translation of the data. In a streaming translation, when the first element of a joined pair is translated, its future partner does not yet exist in the target database. Somehow the connection to the partner must be indicated. It is a problem to recognize and annotate the target database with the various forms of joins and relationships that may be encountered in a streaming translation of the source database. A related problem is capture and update of geometric data during translation from one GIS or CAD Tool database to another. Geometric data is frequently joined to objects in both the source and target databases using a variety of techniques. The geometry data again must be temporarily stored in the target database, prior to its final expression in the target database.
Compounding the problem is the fact that in sophisticated databases a large variety of data structures are used to encode joins, including common field values, special tables, and pointers to locations in memory, to name a few. Some form of the connection data from the source database is stored temporarily in the target database. As presently practiced in the art, the means for storing such connection and geometric data was expansion of the target data model, a difficult and inefficient process. Moreover, after translation is complete, the expansion features of the target database have no further use, and may create inefficiency or expose trade secrets.
It is evident from the above discussion that a need exists for improved methods and structures for effective streaming translation of a source database to a target database.